The objectives of this study are: 1. To isolate, identify and synthesize the sex pheromones in ticks, the presence of which is suggested by bioassays done with crude extracts from females of 3 species. 2. To determine the source(s) of the sex pheromone(s) within the tick's body. 3. To determine whether sex pheromones are produced and/or released only at specific periods of adult life (e.g. during blood sucking and after blood sucking). 4. To determine how the sex pheromone(s) and synergists, if any are used in the search for and selection of mates by adult ticks. 5. To explore the potential for using the synthetic pheromones and detailed knowledge of its role in reproduction to manipulate and disrupt mating success of the tick population. 6. The studies will be done with the American dog tick, Demacentor variabilis, and the Rocky Mountain wood tick, Dermacentor andersoni, both examples of hard ticks (Ixodidae) and the relapsing fever tick, Ornithodoros tholozani, an example of a soft-bodied tick (Argasidae).